Connection-less protocol/ UDP

- The user datagram protocol (UDP) is called as connection-less, unreliable transport protocol.
- It provides process to process communication instead of host to host communication.
- UDP is very simple protocol using minimum of overhead.
- If a process wants to send a message without the care of reliability then it uses UDP.
- UDP takes much less interaction between sender and receiver than using TCP and SCTP.
- UDP packets called as user data gram having the fixed size header of 8 bytes. Following figure shows the UDP header.
user datagram format, computer networking
1) Source port number
This is the port number used by the process running on the source host. Basically it is 16 bit long, means that it's range is from 0 to 65, 535. If the source host is the client, then most cases, port number is an ephemeral port number, means it lasts for very short time. If the source host is the server, then the port number in most cases is very well known port number.

2) Destination port number
This is the port number used by the process running on the destination host. Again it is 16 bit long. If the destination host is the client then most cases, the port number is very well known port number. If the destination host is server then the port number is an ephemeral port number.

3) Length
This is 16 bit field that defines the total length of the user datagram

4) Checksum
This field is used to detect errors over the entire user datagram.





Comments

Post a Comment

Popular posts from this blog

Articulation point of graph / Biconnected components and DFS traversal

Image
In the connected graph G, a vertex V is said to be an articulation point if and only if the deletion of vertex V disconnects the graph into two or more non - empty components. For more precisely satisfy this concept, consider the following connected graph   In this graph, basically vertex 2 is an articulation point, as if we delete the vertex, it will disconnects the graph into two non - empty component.
Read more

Brief shortnote on Requirement elicitation and requirement analysis

Image
- Requirement elicitation means gathering of requirements. - Perhaps it is most difficult, critical, most error prone and most communication intensive aspect of software development. - The most important goal of software requirement engineering is to find out what the customer really wants. - The users need can be identify only by understanding expectation of the user from the developers. - Requirements are gathered by asking the question to user and writing down their answers and their exceptions of the software that how he want to use software. - Gathering the requirements of users is the most difficult part of the software development, because both developer and user have different mindset regarding the software. - Here, communication of both the parties are the most essential for software product. - There are number of requirement elicitation method. https://en.wikipedia.org/wiki/Requirements_elicitation   - Some people think that one methodology is alway
Read more

Requirement Engineering

Image
- Requirement engineering produces one large document, written in natural language, contain a description of what the system will do without describing how will it do. - Requirement engineering is the discipline application of proven principles, methods, tools and notations to describe the proposed system’s intended behavior and its associated constraints. - This process contains the four steps as shown in fig i] Requirement Elicitation This is also known as gathering of requirements. Here the requirements are identified with the help of customer and existing system process are available. ii] Requirement Analysis Requirement analysis     are start with requirement elicitation. Here the requirements are analysis in order to identify inconsistencies, defects, omission etc. iii] Requirement Documentation This is the end product of requirement elicitation and analysis. The documentation is very important as it is the foundation of the software. iv] Requi
Read more